Brake



0ct. 12, 1937. V E, BR|E 2,095,752

BRAKE Original Filed Nov. 22. 1950 5 Sheets-Sheet l F'IGJO IN VEN TOR.

LUg GER E. LABRiE ATTORNEY L. E. LA BRIE Oct. 12, 1937;

BRAKE 5 Sheets- Sha e 3 Origin'al Filed Nov. 22, 1933 I I I l 1 .h

E m N MB .L R 7E G D .U L

- ATTORNEY Oct. 12, 1937. E. LA BRIE 5 BRAKE.

Original Filed Nov. 22, 1933 5 Sheets-Sheet 4 Fla/4- IN V EN TOR.

LUDGER E. LA BRIE FYGJG I lG./7 ATTORNEY iii u- Oct. 12, 1937. L. E. LA BRIE 2,095,752

BRAKE Original Filed Nov. 22. 193'.) 5 Sheets-Sheet 5 I He. 2/

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INVENTOR.

LUDGER E. LA BRHE Patented Oct 12, 1937 2,095,752

UNITED STATES PATENT OFFICE- BRAKE Ludger E. La Brie, Detroit, Mich., assignor to Bendix Brake Company, South Bend, Ind., a corporation of Illinois Application fi ovember 22, 1930, Serial No. 497,383 Renewed October 12, 1936 4' Claims. (01. can-54.6)

This invention relates to brakes, and is illusmobile chassis showing the arrangementof the trated as embodied in a .novel system of hy--- parts of asystem of hydraulic brakes; draulic brakes for an automobile. Figure, 2' is a side elevation of the'chassis One feature of the invention relates to applyshown in Figure 1; ing pressure, preferably through the medium of Figure 3 is a section through the master cyl- 5 air or other yielding pressure means, to the reinder assembly of Figure 1; serve supply of liquid in a reservoir connected Figure 4 is a corresponding section through a to the hydraulic system. This not only keeps the modified form of master cylinder assembly; system full of liquid and in that way obviates Figure5 is a section corresponding to the right- I leakage of air into. the system, but also keeps hand portion of Figure 4, but showing a different 10 the entire system under a pressure which is too connection between the piston and piston rod; light to apply the brakes but which is sufiicient Figure 6 is a section through the liquid reser-v to prevent any formation of a vacuum which "voir of the hydraulic system shown in Figures might suck air into the line. l and 2; 5 It will be appreciated that the presence of any 'Figure '7 is a corresponding section through substantial amount of air in the lines of a hya different form of liquid reservoir; draulic brake system renders the system almost Figures 8 and 9 are sections at right angles to inoperative, as all of the brake-applying moveeach other through the particular form of liquid ment of the parts is then taken up idly in comreservoir which is illustrated in Figures 1 and 2 go pressing the air. The great advantages of a and which in some respects is the equivalent hydraulic brake systemdepend'to a great extent of those shown in Figures 6 and 7; V on the non-compressibility of n the operating Figure- 10 is a section through the cylinder at q r 1 -t e brake showing the connection thereto of Various desirable and illustrative arrangethe hose coupling or the like from the operating ments are shown for keeping the liquid in the lines, and illustrating particularly the arrange- 5 reservoir under pressure, and various features of ment of a two-way check valve used in bleeding novelty relate to these particular arrangements. the line; Some of them apply compressed-air as a pres- Figures 11 and 12 are sections through fittings sure medium, and others'utilize vacuum, for e X-- containing different types of two-way check ample the suction of theintake-manifold of the valves which may be substituted for the one 30 engine, to supplythe air pressure on the liquid. shown in Figure 10;

Other features of the invention relate to the Figure 13 is a vertical section through one ofconstruction of the master cylinder "andof the the brakes just inside the head of the brake "Wheel y d several o m of bot being drum and showing the friction means of the shown. These features have to do with sealing brake in side elevation; 35 the partsagalnst leakage, to an arrangement for Figure 14, is a'section on the line l4l4 of bleeding the lines i. e. filling them with liquid Figure 13 and showing the mounting of the end and getting rid of entrapped air, and to an arparts of the brake shoes or their equivalents and rangement of a two-way check valve in itself h th e parts n age the applying means; w 40 embodying substantial novelty, to facilitate the Figure 5 is a transverse ti through th 40 wheel cylinder of" Figure 13 on the line |s |s Another phase of the invention relates to the of Figure). construction and arrangement of the parts of Figure 16 i a setion on the line |6 |5 of v bmke proper to permit e of a powerful ure 13 and showingone of the steady rests for 4.; shiftable-anchorage type of brake, preferably anthe brake shoes; as? "ev rgreens: it??? its; me 11 a new on M of g q ure.13 and showing another steady rest;

through the brake-applying pistons.

The above and other objects and features of r partial P to r 5 the invention, including various novel and de- 1119,1131) Part of Figure 13 and showing sirable details of construction, will be apparent fifid form of applying and anchoring means;

from the following description of the illustra- Figure 19 is a Section t ou the modified tive embodiments shown in the accompanying form of anchoring and applying means-on the drawings, in which: line l9--l9 of Figure 18;

Figure 1 is a top plan view of part of an auto- Figure 20 is a partial section on the line 201-20 of Figure 18 and showing the anchoring and applying means in side elevation;

Figure 21 is a partial vertical section corresponding to Figures 13 and 18 and illustrating a third form of anchoring and applying means;

Figure 22 is a section through the third form of anchoring and applying means on the line 22-22 of Figure 21; and

Figure 23 is a partial section on the line 23-23 of Figure 21 showing the means for anchoring the brake shoe on the end of the wheel cylinder.

The chassis shown in Figures 1 and 2 includes the usual chassis frame 30 supported by the usual springs on front and rear axles (not shown) carried by front wheels 32 having brakes indicated generally at 34 and on rear wheels 36 having brakes indicated generally at 34. The brakes 34 may be substantially as more fully described below andas illustrated in-Figures 13 to 23.

The brckes are intended to be operated by a hydraulic system including flexible hose connections 38 adjacent the four wheels and communicating by suitable pipes 40 carried by the chassis frame 39 with the outlet 42 of a master cylinder assembly 44 which may be of one of the forms shown in Figures 3, 4 or-5 and which contains an operating pistonconnected by a piston rod 46 with the usual brake pedal 48. The hydraulic system is kept full of liquid by means of a reservoir 50 which may be of one of the forms shown in Figures 6, 7 or 8 and which is mounted on the dash above the master cylinder and on the opposite side of the dash from the driver. The

. reservoir 50 is connected to the master cylinder 44 by means such as a flexible conduit 52.

The form of reservoir shown in Figures 8 and- 9, and which is shown for convenience diagrammatically in Figures 1 and 2 includes a stamped steel container divided vertically into two parts by a flexible diaphragm 54, which may be made of rubberized fabric or-other flexible material which will not be affected by the liquid used in the hydraulic system. The part 56 to the left of the diaphragm in Figure 8 contains the reserve supply of liquid,- which may be introduced through a filler cap 58 and is formed with an outlet 60 to which the conduit 52 is attached. The part 62 above the diaphragm in Figure 9 is provided with means such as an ordinary tire valve 64 so that it may be filled with compressed air from a tire pump or from the usual air line found in filling stations and garages. It is intended that a pressure of some ,ten pounds be carried in the space 62, this being just sufficient to insure that the entire hydraulic system is at all times under a pressure sufilcient to prevent any sucking in of air and which is yet light enough so that it does not actually apply the brakes.

ing a sort of piston adapted to compress a flexible bag or auxiliary diaphragm device within which the liquid is contained and which communicates through an outlet 82 to the conduit 52. By this arrangement the vacuum of the intake manifold maintains air pressure through the opening I4 on liquid serving as before to keep a pressure of some ten pounds on the light hydraulic system. In order to prevent undue pressure being built up, I may provide an inwardly opening check valve 84 for the space 68 which is held by a spring having such a tension that the'valve will open when the pressure in the space 68 drops below the critical predetermined limit.

In the arrangement of Figure '7, the connection '66 from the intake manifold opens into a flexible corrugated metallic diaphragm 86 which is cupshaped in form and which is secured at its lower mouth to a stamping 88 secured to the cap 90 closing the lower end of an external housing 92. The upper end of the corrugated cup-shaped diaphragm 86 is secured to a base stamping 94 which urges downwardly a corresponding base 96 closing the upper end of a similar corrugated metallic diaphragm 98 which contains a reserve supply oi liquid and the mouth of which is closed by a stamping I00 secured to the cap 90. The liquid inside the cup-shaped diaphragm 98 communicates with the conduit 52 through an outlet I02.

Both the containers 80 and 88 may be filled by providing a suitable filler spout I04 with a re- I movable cap.

The master cylinder indicated generally at 44 in Figures 1 and 2 may be of any of the forms shown in Figures 3, 4 or 5. The form shown in Figure 3 includes a cylinder proper I06, which may be made as a casting, and one end of which is permanently closed by a cap I08 containing the outlet 42 to the conduit 40. Inside of the cylinder I06 is arranged a floating piston I I0 having a cylindrical extension II2 upon which is sleeved a sealing member such as a rubber gasket II4 slidably engaging the inner face of the cylinder I06. The sealing member- I I4 is held in place against the face of the piston I III by means such as a spring II6 confined between the sealing member H2 and a. washer or equivalent stop II8 on the forward end of the extension H2. The piston H0 is urged in a direction to release the brakes by means such as a light spring I20 confined between the cap I08 and the stop at the end of the extension I I2.

The floating piston H0 is forced to the left to apply the brake by means such -"as a secondary or operating piston I22 formed with a central axial opening through which the piston rod 46 passes and which is formed with a spherical seat receiving a spherical head I24 on the end of the piston rod. The spherical head I24 is embraced between the seatformed on the piston and the semi-spherical concave bottom of a plug I26 threaded into the opening in the piston, thus forming a ball-and-socket joint. The idle or released position of the auxiliary piston I22 is determined by engagement of its base-with a cupshaped stamping I28 threaded on the end .of the cylinder I06 just beyond a flange I30 which is adapted to engage and be bolted to a part of the chassis frame of the car.

The auxiliarypiston I22 is formed with an extension I32 disconnectedly engaging a projection I34 on the rear end of the piston IIO so that the piston I22 forces the floating piston III] to the left to apply the brakes, but does not compel the floating piston to return to its idle position when the brakes are released. The space I36 between the two pistons is in communication by a passage I38 with the conduit 52 from the liquid reservoir. so that any suction created by p nsated for by the introduction into the chamher I36 of compensating liquid from the reservoir.

the force for returning the piston III) should floating piston I III will finally move far enough to the "right in Figure 3 to clear a port I38 communicating with the conduit 52 through a passage controlled by a spring-pressed poppet valve I40 which is pushed upwardly by the conical return endof piston II 0 when the brake is fully released. The upward movement of the valve I40 establishes communication between the liquid in the reservoir and the space in the cylinder I06 in front of the floating piston H8 and thereby communicates the pressure in the liquid reservoir to the entire hydraulic system. As soon as the brake is applied, however, the piston 8 outs ofi the port I38'and atthe s'ametime allows the valve I40 to seat itself to cut off back pressure from the hydraulic system to the liquid reservoir and chamber I36. 'This, however, does not interfere withthe free communication between the liquid reservoir and the space between the pistons I I0 and I22, which space therefore serves at all time's as a liquid seal eifectively preventing any building up of suction anywhere in the assembly which might cause the introduction of air.

In the arrangement of Figure 4, the piston rod 46 disconnectedly engages a piston I42 in a cylinder I44 which is generally similar. to the pistons described above except that there is only one piston and except that when this piston closes off 'a port I46 communicating with the liquid reservoir, during the first part of the brake applying movement of the pedal, the return of .any liquid from the space in front of the liquid to the reservoir is prevented by a'spring-pressed ball check valve I48 some distance in advance of the piston and which controls a passage I50 partly formed in the cylinder casting and partly formed preventing, the building up of suction sufliciently to introduce air into the system.

The rear end of the piston I42 is shown as sealed by a gasket or the like I56 held against the conical wedge-shaped seat on the end of the cylinder by a conical wedge ring I58 held by a spring I60. The wedge surfaces confining'gasket I56 squeeze it inwardly into liquid tight en- 1 gagement with the skirt of the piston I42.

Thearrangement in Figure 5 is substantially the same as that in Figure 4 except that the piston rod 46' is connected to the piston I52, corresponding to the piston I42, between theballand-socket joint of Figure 3. In this arrangement, the positive return of the piston has some tendency to cause a suction in the cylinders which, however, immediately permits the valve I48 to open, whereupon liquid enters from the reservoir and againsbreaks the suction. If the piston I62 reaches its completely released posi- In this connection I prefer that most of,

tion before the brakes at the wheels are com- I pletely released, the latter will continue to force liquid backwardly into the cylinder, whereupon enough liquid is forced up through passage I46 to compensate for excess liquid which has entered past the valve I48.

A connection between the master cylinder and each of the wheel cylinders I64 preferably includes, immediately adjacent the wheel cylinder,

'a fitting I66 within which is arranged a twoway check valve which is utilized to 'control bleeding through a passage I68 which is normally closed by a plug-threaded into an outlet opening I10. In the arrangement of Figure 10, fitting I66 is formed internally with a double diameter bore. Inside of the larger diameter portion of the bore is a cupshaped piston valve "I12 urged by a spring I14 against a conical seat at the junction of thesmall and large diameter parts of the bore. The valve member I12 is formed with an opening base communicating with the small diameter part of the bore and which is normally closed by a ball check valve I16 urged there-against by a spring I18. When it is desired to bleed the system to' fill it with liquid or to remove air which has become entrapped therein, the plug is removed fromthe' outlet opening I10 andsuflicient liquid is forced from the master cylinder and the reservoir through the various conduits 38 and 46 to fill all the wheel cylinders I64 and pump an excess through-the four outlets I10 sufficient to insure the removal of all the air. When this is being done, the ball check valve I16 yields to permit the passage of the additional liquid; During the application of thebrake; when pressure is applied to the system, liquid passes the ball check valve I16 through opening in the base -of the cup-shaped valve member I16 in sufficient quan tity to force the brake shoes against thedrum. When the brake is released, the return springs force this additional liquid backwardly, whereupon the cup-shaped valve member I12 moves back off. its conical seat and permits the additional liquid to leak back around between the valve member and the large diameter part of the bore of the fitting I 66.

In Figures 11 and 12 are shown two other forms of two-way check valves which may be provided in the fitting I 66. In the arrangement of Figure 11, the cup-shaped valve member I12 is arranged as-inFigure 10, but in place of the ball check valve I16, I provide another piston valve member I held between spring I18 in a position to close the opening in'the bottom of the valve member I12. In the arrangement of Figure 12, a hollowvalve member I82 is held against the above-described" conical seat between spring I14, a ball check valve I84 being arranged inside of the valve member I82 and held in place lightly by a spring I86.

' The brake shown in Figures 13 to 17 include a rotatable drum, I90, at the open side of which is arranged a suitable. support such as a backingplate I92 and within which is arranged the friction means of the brake. I prefer to utilize a brake of the shiftable-anchorage type, which may embody floating friction means shown as including a pair of by asuitable adjust joint I98 of any desired form connected to the lower ends of the shoes by pivots 200. Theshoes may be positioned by means such as steady rest pins 202 carried'by the backing plate and engaging the webs of the shoes. and against which the webs of the shoes are urged by means such as springs 204 tensioned between the shoe webs and backing plate and conical springs 266 confined between the shoe webs and nuts or other stops 208 on the ends of steady rest pins 2Ill carried by the backing plate and passing through relatively large openings 2I2 in the shoe webs.

The particular brake shown in Figure 13 is applied, against the resistance of a return spring 2 tensioned between the shoes, by novel means which includes the above-described wheel cylinder I64 whichis attached to the backing plate by means such as screws 2I6, as shown in Figures 14 and 15. I

Within the cylinder I64 are a pair of floating opposed pistons 2I6, against the heads of which a spring 226 holds a pair of rubber sealing cups 222. The floating pistons act to apply the brake in such a manner that one or the other of the shoes may anchor by engagement of one of the thrust members 224 connected to the ends of the shoes by pivots 226. The pivoted thrust members 226 engage anchor cups 228 which are arranged to transmit the brake applying force from the floating pistons 2I8 to the thrust members 224 and the bases of which also anchor against the ends of the cylinder so that the braking torque is taken from one or the other of the thrust members 224 against cylinder I64 without acting on the pistons 2I8. Suitable boots 230 of rubber or the like may, if desired, be provided to close the ends of the cylinder I64 and house in the above-describedanchoring and applying parts. v

In the arrangement of Figures 18 to 20, the shoes 294 and 296 are arranged with reinforced rounded projections at their ends for direct engagement with two anchoring parts in the form of auxiliary pistons 328 engaged by the skirts of the floating pistons 3"! corresponding to the above-described pistons 2! and the brake of Figure 13. Caps 330 may be mounted over the ends of the pistons, if desired, to house in as much as possible of the operating parts. In this arrangement, one or the other of the shoes 294 or 296 anchors through the medium of one of the auxiliary pistons 328 against one or the other of the ends of the cylinder I64.

In the. arrangement of Figures 21 to 23, the shoes 394 and 396 are formed with reinforced rounded projections at their ends in direct engagement with the floating operating pistons M8. The torque of the brake in this case is transmitted to the ends of the cylinder I64 by means such as transverse anchor pins 428 seated in the ends of the shoes and preferably mounted there permanently by having narrow center portions which are forced into the webs of the shoes as far as permitted by flanges on the ends which engage the sides of the webs. The transverse anchor pins 426 seat in correspondingly shaped notches in flanges integrally formed in the ends of the cylinder I64.

Tn all three of these embodiments, the brake .is arranged to anchor at one end when the the brakedrums are turning.

The structure of the wheel brake cylinder and the combination thereof with the check valve is also shown and is described in my copending application Serial No. 92,798. The structure of the check valve is also shown and described and is claimed in my copending application Serial No. 93,325. The structure of the piston rod coupling is also shown and described and is claimed in my copending application Serial No. 92,062. The wheel brake structure is also shown and. described and is claimed in my copending application Serial No. 93,447, and the reservoir is also shown and described and is claimed in my copending application Serial No. 77,733.

While a number of illustrative embodiments of the invention have been described in detail, i is not my intention to limit its scope to these particular embodiments or otherwise than by the terms of the appended claims.

I'claim:

1. For use in a hydraulic brake system, a master cylinder piston arranged.- to move forward in applying the brakes; a master cylinder comprising a casting formed with a main bore and with a forward intersecting smaller bore and a rearward intersecting smaller bore, the smaller bores forming ports for. said main bore, the forward smaller bore having a threaded portion, the port formed by the rearward smaller bore being arranged immediately in advance of the normal retracted position of the master cylinder piston and allowing flow of liquid in either direction when said master cylinder piston is in its retracted position and the port formed by the forward smaller bore being arranged substantially in advance of the first mentioned port, said casting beingalso formed with a third bore connecting said two first mentioned smaller bores; a reservoir; a threaded plug formed with a central bore and inserted in said threaded bore and closing the opening thereof to the atmosphere; and a valve in said plug bore comprising a movable element and a spring urging said element toward its seat, said valve being arranged to allow substantially free passage of fluid from said reservoir through cular groove, an inlet port connected to said plug bore and leading from the center of said recess to said chamber and another inlet port leading to said chamber and connected to said circular groove, a piston in said pressurechamber, and a valve in said plug bore for controlling the first named of said ports.

3. In a hydraulic brake apparatus, a master cylinder formed with a pressure chamber, with a recess formed in one of the outer faces thereof, and with a pair of inlet ports leading from said recess to said chamber; a piston insaid'pressure chamber normally positioned rearwardly of both of said inlet ports; a. valve for controlling one of said ports, said valve comprising a plug secured in said recess and formed with a longitudinal passageway communicating at one end with one of said inlet ports and having a shoulder, a valve element in said passageway adapted to seat on said shoulder, and a spring bearing on said 'ele-* ment, said plug being also formed with a transverse passageway communicating with :said longitudinal passageway and with said other port; a

reservoir; and a connection from said reservoirto the end of said longitudinal passageway opposite to its connection with said inlet port.

4. In a hydraulic brake apparatus, a master cylinder formed with a forward inlet port and witha rearward inlet port, with a pressure chambar, and with a recess; a plug in said recess having a circular groove around it communicating with said rearward inlet port, having a longitudinal passageway communicating at its inner end with said forward inlet port, and having a transpassageway with the groove; a piston in said pressure chamber normally positioned rearwardly of said rearward port and being arranged to be moved forwardly over said port; a reservoir; a connection from said reservoir to the outer end of said longitudinal passageway; and a valve in said longitudinal passageway for controlling the movement of said fluid between said forward port and said longitudinal passageway.

LUDGER E. LA BRIE. 

